148161

Appears in sequences

• Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n-4)/2.at n=20A048066
• Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n+3)/3.at n=20A048088
• Numbers k such that sigma(k-phi(k)) = phi(k).at n=25A070170